Laminated rubber



Patented Aug. 39, 1927.

outrun. s'raras career enrich.

, METRE C. EETERSON, 01? AKRON, OHIO.

LAMINATED RUBBER.

lilo Drawing.

side of raw or unvulcanized rubber.

Vulcanized rubber is commonly made by mixing or compounding the crude rubber,

with sulphur; a small amount of an organic accelerator or a. comparatively greater amount of such inorganic meterials as litharge, lime, or magnesium oxide which accelerate the vulcanization of the mix by shortsuing the time or lowering the temperature usually necessary; varying amounts of other pigments added to modify the physical properties of the vulcanizate such as strength, elasticity, hardness, specific gravity and color; and then heatin the compound until cured or vulcanized.

lt has heretofore been attempted to pro duce rubber articles as above described by 1 uniting sheets or laminations, some of whic contain sulphur, sulphides, metallic oxides, or the like and other of which do not, the idea being that the first mentioned sheets will become cured or vulcanized and the last mentioned sheets will remain raw or uncured.

This has not met with any appreciable success, due to the vulcanizing agents, particularly sulphur and sec erators migratory in nature, getting upon a id penetrating into "the layers which it is desired shall not become vulcanize and so causing these layers to be vulcaniae as well as the other laminetions.

I have found that curin'g of these layers can be prevented by incor crating therein, in the compounding thereo certain materials which neutralize the effect of the vulcanizing agent. Consequently any of this agent getting on or into the layerswhich it is desired shall not be cured, produces no eflect upbiifthese layers even when they are heated yvitb the other layers in vulcanizing the utter.

' 1 will describe by way of example, articles 5 formed and the process by which they are Application filed January 3, 1927. Serial No. 158,828.

formed, in producing one particular material suitable for tire patches.

Two rubber compounds are produced, one, hereinafter called the face compound, which it is desired to use for the side of the articles which is to remain raw or uncured; and the other, hereinafter referred to as the backing compound, for the side which it is desired shall be cured.

The face compound is compounded of the following materials:

Thin pale crepe 58.0 Barytes 38.0 Rosin oil -Q. 3.0 Sodium bisulfate 1.0

The backing compound is compounded of The face compound is rolled or calendered to a thickness of about .017 of an inch and. is run from the calender upon a suitable fabric, such as Holland. The backing co1npound is rolled or calendcred to a thickness of about .030 of an inch and superposed while hot upon the face compound, which has been previously placed on the fabric, as above stated.

Next, the exposed surface of the backing compound is starched. I

After this, the built-up sheet is put into an air heater and maintained at a temper- M ature of centigrade for between 24: and 36 hours. During this heating, the backing compound becomes vulcanized or cured, part 015 the sulphur uniting with the rubber while whatever sulphur and accelerator may have penetrated the face compound has its action neutralized by the sodium bisulfate incorporated therein. The action oi the sulphur. and zinc oxide as vulcanizing agents. is, aided, and the time of vulcanizing shortened by the presence of the diorthotolylthiourea. The lithopone, barytes, etc., act merely as fillers. i

I find that the sodium bisulfate very o"'- inorganic acid such as hydrochloric suiphuric, or phosphoric; small moon-no; of acid omits of alkali or alkali earth metals; or small amounts of orgzu'iic acids, such as acetic cc i lactic acid, or tannic acid.

While I have described my invention ciiovc. with some pm'i'iculmhity as applied to id. c particular compounds sctgforth for tho manufacturer of (mo form of tire patches, obviously they may bc applied to many oihcgf compounds and io H10 mi king many other :l1.ti(;1(3,. 2111611, iiicz'coic, do not limit myself 10 fiac precisc dctai-is ciosclibcd but claim as my invention all cmboiiiments thcrcot' failing: within the scope 'ihc appended claims.

v 1%: claim: 1, An article composed of two i'ubbci' c0mpounds, one of which, as compoundd, coo wins 2, vulcanizin agent and a vuiczmizing moderator, and the other of which, com-- pounded, is from 'vuicanizing agents and contains inci'criolwhich ncun-aiizcs tho ci'ii'ccfs of such vulczmizing agents. 1

2. in :li'iii'ifi) madc of two iayers of mi;- Lor, one of which contains u' iuicnnizing "cot onrl the other of which, as coa'npoumico, free from vulccnizing zigcntc and. con-- mm. material capobic of neutralizing the I o such agents. 3 The process oi pi'oducmg :1 rubbocun i iclc which comprises making cwo rubber cowpounds one of: which coniainsa vulcaniicing; agent and tho oihor of \i'hif. frcc vuicaiiizing agents and contains mote i'ici neutralizing the effect of mid agent, an aiiiclo wiiih parts; which it is desired. shall be vulcanized. of the iimi moo iocod compoutnei, and. par which it is do Shall not be volcanic i a a sccon'i tiooco compomld cnci the .hectmg mo pounds of rubber ombic mi-icic 11315;} the fi s25 moor oocci pound is vulcanized,

4;. Tho process of proci'iiiciog chcc ss having one side oniy 'vuiconizcci, which comprises making two compounds of maobor, one containing the 'vulccnizinrr we '6 and the oiibcr being free from Vulco 45mg :Lgcnts mini containing material neutralizing izhc cfi'icct of mid agent,forming said compounds into shoots superposiiig soil? shoots and heating tho entire laminated chock until the first mentioned compound is vuiczmizcd.

The process of forming robber shoots having; one side vulcanized and the other is raw, which compitisos llltliiiilg 'iwo coinone containing the voimnizing agent-mid voiconiziog accelerator and tho ocher being fr co from oiconizing its and izz-ontainiiog mzicriai "which nounmiizco the effect of said vulczmizing agent,

ccicncici'ing the second mcntioncd compound to chc thickness oi row .i'oiJ-Eoci" do so Fad in tho finished product delivering i116 some upon a shoot of ficxiblc moicriai, coicndoriog tho other compound in the thick of ,"diQHDIZGCi material cicsircd in ihc' occas- .iinmhed shoot supcrposing said compo/woo upon (he first incntic, CORHPOUIA'IL stcaroi1- 'ing tho exposed surface of sc m :o-

ion 4i laying and ihon booting c composii shoot imi'zuihc outer lo cw has vuicci of forniing sheet of 1 I flea-cm chomc tci'istics on ccch hich con'ipriscs providing 33111 i of dii'i'cz-cnb rubber cc mods, of said compounds having culczmizing :igcnb and o vulcanization ccccicrzitom othcr'of said compounds h ivViY no vu1cc11- icing cgcnt and containing no substance to mmntoruct ihc effect of any vulccnizing agent that focy come in contact therewith SUPQIQU composite sheet until the first mentioned compound completely vuiccnicod.

ag said shoots and heating the 1 

